What is it? This is the new 2012 model year version of one of the more powerful petrol-engined BMW 5 Series models.
The 528i now has a downsized 2.0-litre turbocharged, four-cylinder engine rather than a non-turbo six-cylinder.
The key aim of the downsizing was to reduce fuel consumption and emissions, and although peak power is slightly down compared with the outgoing engine, torque is significantly improved.
CO2 emissions fall from 188g/km to 159g/km, average economy improves from 35.3mpg to 41.5mpg, and 0.7sec is shaved from the 0-62mph sprint, meaning a brisk 6.2sec time.
Besides this efficient new turbo engine, which BMW labels Twinpower, all new 5 Series cars now get Bluetooth, front and rear parking sensors and two-zone air-conditioning.
Also new is the grandly labelled 'Driving Experience Control', a switch near your left knee that allows the driver to shuttle between Sport+, Sport, Comfort and Eco Pro modes.
It adjusts accelerator reaction, steering effort, the automatic transmission's responses, the level of anti-skid intervention and, if dynamic shock absorbers are fitted, the character of the ride.
In addition, the Eco Pro mode helps you drive more economically by minimising the power drain of the air-conditioning and other equipment, by issuing driving tips and providing a rolling read-out of your consumption in 15-minute chunks.
What's it like to drive? The 5 Series was an impressive car before this engine upgrade, and it's all the more so now.
Substantial thrust is available from well below 2000rpm, leaving you in no doubt that this is a sports saloon. Most of that pull is in the mid-range, so if you're driving a manual it pays to change up before reaching 5000rpm.
With the eight-speed automatic and that's how most 528is will be ordered a succession of imperceptible gearshifts provide an effortless way of enjoying truly authoritative performance.
There's a minor trade-off compared with the old six-cylinder engine, the four-cylinder unable to match its super-smooth, turbine-like wail, but the new engine is so quiet that you barely notice.
The 'Driving Experience Control' provides a worthwhile diversion, especially if you order the car with Variable Damper Control, which allows you to alter the ride from near pillow-soft to sportily firm. Indeed, drive the car in Comfort with the fuel-saving Eco Pro mode, and its character changes quite noticeably from the spirited nature in Sport and Sport+.
What's it like inside? This is a well-crafted, quietly luxurious car, and you feel that from the moment you open the door and climb inside.
Careful colour selection can produce a truly inviting interior, as well as one that's well constructed and conveniently arranged.
As you'd expect, there's plenty of space up front and the adjustable seat ensures excellent driver comfort, while those in the rear will enjoy decent space, if not quite enough room to sprawl.
BMW's iDrive infotainment system is one of the best around, and the excellent refinement is just what's needed for long hours behind the wheel.
Should I buy one? The significance of this new 528i is that the engine is now efficient enough to stand comparison with the diesel models in the range, especially now that it attracts a 21% company car tax rating rather than the previous 27%.
The 525d diesel, for instance, is slightly slower and costs a couple of thousand more, and while it attracts a 19% company car tax rating and is 4mpg more economical, it's worth remembering that diesel is more expensive than petrol.
The result is that it's now easier to justify the petrol 528i, which is a measure of how successful BMW has been in improving efficiency.
On top of that, there's the general competence and appeal of the 5 Series itself, its only major drawback being that you must order a few items from the options catalogue, not least the Variable Damper Control, if you want it to drive as well as a BMW should.
In cold terms, a diesel 5 Series still makes more sense, but if you like petrol engines your indulgence will now cost you usefully less.
What Car? says